Cooling plate for metallurgical furnaces

ABSTRACT

A duct for a cooling medium is formed by a channel (2) closed by a rear and end cover plates (3, 4) embedded in a metal of a plate (1) so that the rear cover plate (3) is free from said metal. On the rear cover plate (3) are provided branch pipes (5) for feeding the cooling medium into the duct and discharging the same therefrom.

TECHNICAL FIELD

The present invention relates to cooling equipment used in metallurgicalproduction, and particularly to cooling plates of metallurgicalfurnaces.

Cooling plates of such a type, comprising a metallic plate proper and aduct for a cooling medium, provided in said plate, are used inmetallurgical shaft furnaces, e.g. in blast furnaces. These coolingplates are identical irrespective of whether they are flat or providedwith projections cooled by ducts extending therewithin, said projectionsadapted to support refractory brickwork of the furnace. Since thecooling plates utilized in the same furnace, with or without supportingprojections are similar in design, the cooling plate being the object ofthe invention will be further called "a cooling plate of the abovetype".

BACKGROUND ART

Cooling plates of the above type (see Andonyev S. M. et al.,Okhlazhdenie domennykh pechei, Moscow, "Metallurgia", 1972, s.216-220)are manufactured by pouring cast iron around steel cooling pipes so asto embed them in said cast iron, which forms a body of the plate. Suchplates are cast either flat or provided with supporting projections.Said pipes are also used for cooling the projection, for which end thesepipes are bent so as to enter the projection body. Cooling of saidprojections may also be effected through separate cooling pipes.

The cooling plates of the above type have portions which are locatedbetween the cooling pipes and at the elbows thereof, in which portionsthere exist a non-uniform thermal field and a low rate of heat removal.The non-uniform thermal field produces thermal stresses within the plateand pipes. The thermal stresses are also caused by the fact that castiron and steel have different coefficients of thermal expansion.Furthermore, in the zone of outlet portions of the pipes there existresidual stresses formed during the process of pouring cast iron aroundthe steel pipes. In the process of manufacturing the cooling plates thesteel pipes may be carburized and, consequently loose plasticity inspite of application of protective coatings, e.g. marshalite ones. Theabove disadvantages result in a shorter service life of the coolingplates.

In the operation of the prior art cooling plates, in the case ofburning-through of the cooling pipes there arise problems of finding anddisconnecting the burnt pipes, and in particular the pipes of thesupporting projections, which pipes are damaged first of all.

The object of the invention is to provide a more stable cooling plate ofthe above type due to a more uniform and intensive cooling thereof.

The object set forth is attained in the provision of a cooling plate ofthe above type for metallurgical furnaces, wherein according to theinvention a duct for a cooling medium is constructed as an upwardlyextending channel closed with cover plates at the rear and end sidesthereof, said channel being cast into the plate metal so that the rearcover plate is not embedded in metal, branch pipes for feeding a coolingmedium into the duct and for discharging the same from said duct beingprovided on the rear cover plate.

The cooling plate of such a design ensures a more uniform and reliablecooling due to the elimination of non-cooled angular portions. Since theduct for the cooling medium, constructed in the form of a channel, cancover a large area of the plate, so that the problem of interpipedistances is completely solved. The provision of the branch pipes forfeeding and discharging the cooling medium on the rear side of the coverplate which is not embedded in metal, eliminates the problem of residualstresses in the plate and the pipes, said stresses being caused byjamming of the discharge portions of the pipes and by differentcoefficients of elongation of cast iron and steel, if these materialsare utilized. Besides, a large mass of the channels as compared withthat of the cooling pipes in the prior art cooling plates ensures a moreintensive solidification of cast iron used for cooling plates, therebyresulting in the decrease in carburization of the ducts for the coolingmedium.

It is preferred to introduce the cooling pipe of the projection, formingan enclosed loop of circulation of the cooling medium, into the duct forthe cooling medium. Such an arrangement makes it possible to eliminatelabour-consuming operations of finding and disconnecting the burnt pipesof the bearing projection, since the above pipes are not directlyconnected with an external system for feeding the cooling medium, waterin particular. In this case, uncontrolled entrance of water into thefurnace is eliminated.

To increase the reliability of cooling it is expedient that the duct forthe cooling medium be extending over the whole height of the plate.

BRIEF DESCRIPTION OF DRAWINGS

The invention is further described in terms of specific embodimentthereof with reference to the accompanying drawings, in which:

FIG. 1 is a rear view of the cooling plate of the invention, a portionof the duct for the cooling medium being cut away to illustrate innerstructure thereof;

FIG. 2 is a view taken along the line 2--2 in FIG. 1;

FIG. 3 is a view taken along the line 3--3 in FIG. 2;

FIG. 4 is a view of the cooling plate of the invention, having asupporting projection shown from the rear side, a portion of the ductfor the cooling medium being cut away to illustrate the inner portionthereof;

FIG. 5 is a view taken along the line 5--5 in FIG. 4;

FIG. 6 is a view taken along the line 6--6 in FIG. 4.

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1, the cooling plate utilized to illustrate the presentinvention, is a cast iron plate 1, though other materials are possible,e.g. steel or copper alloys. Channels 2 (two channels in the givenexample) are embedded to their depth in space relationship in the plate1 so that the channel wall is disposed substantially parallel to thetemperature front, the channel legs are not extending beyond the rearsurface of the plate, which is best seen in FIGS. 2 and 3. The channels2 are closed with rear cover plates 3 forming together withcorresponding channels ducts for cooling medium.

In the present embodiment of the invetion the cover plate 3 is a steelsheet welded to the channel legs. It is preferred to provide the coolingducts extending over the whole height of the plate, i.e. to utilize thechannesl 2 equal to the plate 1 in length (the vertical direction inFIGS. 1 and 2). In the upper and lower portions of the plate, or on theend faces of the channels 2 are mounted end cover plates 4 (these coverplates are mounted in the same manner as the cover plates 3) forming anenclosed of cooling cavity. On the end portions of the rear cover plates3, or near the end cover plates 4 are provided branch pipes 5 forfeeding the cooling medium, e.g. water into the cooling duct and fordischarging the same from this duct.

To provide a desired velocity of the cooling medium, within the coolingcavities of the channels 2 there may be built in horizontal baffles 6(FIGS. 1 through 3), successively extending from one of the channel legsand not reaching the opposite leg, thereby forming the movement of thecooling medium, being directed along a zigzag or serpentine path. Toobtain a guaranteed serpentine duct for the cooling medium and tofacilitate assemblying of such a duct, grooves or slots (not shown) maybe made in a sheet forming the rear cover plate 3 in the locations ofthe baffles 6. In the case of the provision of the slots, the baffles 6may extend beyond the external surface of the rear cover plate 3 to weldsaid baffles to this cover plate from outside.

According to another embodiment of the invention, a cooling pipe 7 of aprojection 8 is introduced into the cooling duct, said duct being formedby the channels 2. The pipe 7 is closed and partially filled with thecooling medium. The quantity of the cooling medium in the pipe 7 dependson thermal characteristics of the cooling medium proper and on theoperating conditions, and for this reason is not defined precisely inthis specification. As seen in FIG. 5, a portion of the pipe 7 isdisposed within the body of the supporting projection 8, while anotherportion thereof (namely a condensation portion) is disposed within thecavity of the channels 2, thereby forming a closed loop of circulationof the cooling medium. The condensation portion of the pipe 7 may beintroduced only into the cavity of one of the channels 2, though theembodiment illustrated in FIGS. 4 and 5 ensures cooling of theprojection 8 even when supply into one of the cavities is discontinued.Moreover, the supporting projection may be provided with two pipes 7whose cooled or condensation portions can be located separately withindifferent cooling cavities.

According to the invention, the cooling plate is provided with amounting clamp 9 and openings 10 to receive mounting bolts.

The cooling plate described and illustrated in the accompanying drawingshas the following advantages as compared with the prior art devices:

uniformity and high reliability of cooling the heat-plate, which areensured due to the fact that the duct for the cooling medium has adeveloped heat-receiving surface area;

stresses existing within the plate and the ducts for the cooling mediumare reduced since the branch pipes and the rear cover plates are notembedded in the plate body;

carburization of the walls of the cooling ducts is reduced due to a moreintensive solidification of the plate metal and to the massive nature ofthe channel during the manufacture of the cooling plate;

labour-consuming operations in finding and disconnecting theburnt-through pipes of the bearing projection are eliminated since saidpipes are not connected with the external system of water supply;

uncontrolled entrance of water into the furnace due to burning-throughof the pipes of the supporting projection is eliminated.

INDUSTRIAL APPLICABILITY

The cooling plate of the invention is widely used in metallurgicalfurnaces, and mainly in blast furnaces.

We claim:
 1. A cooling plate for metallurgical furnaces, comprising aduct for a cooling medium and being in the form of a channel formed in ametal plate and oriented in the direction of the height of the plate,said channel having its rear and end sides, respectively, closed withrear and end cover plates, said channel being defined at one side by theplate and its opposite side by the rear cover plate spaced from saidmetal plate, and branch pipes provided on the rear cover plate adaptedto feed a cooling medium into the duct and discharge the same therefrom,said duct having introduced thereinto a cooling pipe of a supportingprojection so as to form a closed loop for circulation of the coolingmedium.
 2. A cooling plate according to claim 1, wherein the duct forthe cooling medium extends along the full height of the plate.